Updating to expect frequency units for clock and trace flags.

Making sure trace frequency is not less than 1/5 of the system frequency.

src/st-trace/trace.c

@@ -98,13 +98,53 @@ static void usage(void) {
   puts("  -V, --version         Print this version");
   puts("  -vXX, --verbose=XX    Specify a specific verbosity level (0..99)");
   puts("  -v, --verbose         Specify a generally verbose logging");
-  puts("  -cXX, --clock=XX      Specify the core frequency in MHz");
-  puts("  -tXX, --trace=XX      Specify the trace frequency in Hz");
+  puts("  -cXX, --clock=XX      Specify the core frequency");
+  puts("  -tXX, --trace=XX      Specify the trace frequency");
   puts("  -n, --no-reset        Do not reset board on connection");
   puts("  -sXX, --serial=XX     Use a specific serial number");
   puts("  -f, --force           Ignore most initialization errors");
 }
 
+static bool parse_frequency(char* text, uint32_t* result, double default_scale)
+{
+  if (text == NULL) {
+    ELOG("Invalid frequency.\n");
+    return false;
+  }
+
+  char* suffix = text;
+  double value = strtod(text, &suffix);
+
+  if (value == 0.0) {
+    ELOG("Invalid frequency.\n");
+    return false;
+  }
+
+  for (int i = 0; suffix[i] != 0; i++)
+    suffix[i] = tolower(suffix[i]);
+
+  double scale = default_scale;
+  if (strcmp(suffix, "hz") == 0)
+    scale = 1;
+  else if (strcmp(suffix, "khz") == 0)
+    scale = 1000;
+  else if (strcmp(suffix, "mhz") == 0)
+    scale = 1000000;
+  else if (strcmp(suffix, "ghz") == 0)
+    scale = 1000000000;
+  else
+    WLOG("Frequency is missing units of Hz, kHz, MHz, or GHz.\n");
+
+  value *= scale;
+  if (value <= 0 || value > 0xFFFFFFFFul) {
+    ELOG("Frequency is out of valid range.\n");
+    return false;
+  }
+
+  *result = (uint32_t)value;
+  return true;
+}
+
 bool parse_options(int argc, char **argv, st_settings_t *settings) {
 
   static struct option long_options[] = {
@@ -150,10 +190,12 @@ bool parse_options(int argc, char **argv, st_settings_t *settings) {
       ugly_init(settings->logging_level);
       break;
     case 'c':
-      settings->core_frequency = atoi(optarg) * 1000000;
+      if (!parse_frequency(optarg, &settings->core_frequency, 1000000))
+        error = true;
       break;
     case 't':
-      settings->trace_frequency = atoi(optarg);
+      if (!parse_frequency(optarg, &settings->trace_frequency, 1))
+        error = true;
       break;
     case 'n':
       settings->reset_board = false;
@@ -272,9 +314,8 @@ static bool enable_trace(stlink_t *stlink, const st_settings_t *settings,
   stlink_read_debug32(stlink, STLINK_REG_TPI_ACPR, &prescaler);
   if (prescaler) {
     uint32_t system_clock_speed = (prescaler + 1) * trace_frequency;
-    uint32_t system_clock_speed_mhz = (system_clock_speed + 500000) / 1000000;
-    ILOG("Trace Port Interface configured to expect a %d MHz system clock.\n",
-         system_clock_speed_mhz);
+    ILOG("Trace Port Interface configured to expect a %d Hz system clock.\n",
+         system_clock_speed);
   } else {
     WLOG("Trace Port Interface not configured.  Specify the system clock with "
          "a --clock=XX command\n");
@@ -444,9 +485,8 @@ static void check_for_configuration_error(stlink_t *stlink, st_trace_t *trace,
     stlink_read_debug32(stlink, STLINK_REG_TPI_ACPR, &prescaler);
     if (prescaler) {
       uint32_t system_clock_speed = (prescaler + 1) * trace_frequency;
-      uint32_t system_clock_speed_mhz = (system_clock_speed + 500000) / 1000000;
-      WLOG("Verify the system clock is running at %d MHz.\n",
-           system_clock_speed_mhz);
+      WLOG("Verify the system clock is running at %d Hz.\n",
+           system_clock_speed);
     }
     WLOG("Try specifying the system clock with the --clock=XX command line "
          "option.\n");
@@ -563,9 +603,13 @@ int main(int argc, char **argv) {
   uint32_t trace_frequency = settings.trace_frequency;
   if (!trace_frequency)
     trace_frequency = STLINK_DEFAULT_TRACE_FREQUENCY;
-  if (trace_frequency > stlink->max_trace_freq) {
+  uint32_t max_trace_frequency = stlink->max_trace_freq;
+  if (settings.core_frequency != 0)
+    if (max_trace_frequency > settings.core_frequency / 5)
+      max_trace_frequency = settings.core_frequency / 5;
+  if (trace_frequency > max_trace_frequency) {
     ELOG("Invalid trace frequency %d (max %d)\n", trace_frequency,
-         stlink->max_trace_freq);
+         max_trace_frequency);
     if (!settings.force)
       return APP_RESULT_UNSUPPORTED_TRACE_FREQUENCY;
   }